1. Field of the Invention
The present invention relates to a ratchet wheel with asymmetric arcuate concave teeth or non-arcuate concave teeth. The present invention also relates to a socket wrench in which the ratchet wheel is mounted. The ratchet wheel with asymmetric arcuate concave teeth provides improved structural strength and improved torque. The ratchet wheel with non-arcuate concave teeth is easy to form and thus reduces the production cost.
2. Description of the Related Art
A wide variety of spanners and wrenches have heretofore been provided. Ring spanners are the best choice for driving fasteners (e.g., nuts, bolt heads, etc) in a limited space that is uneasy to access and difficult to operate all kinds of ratcheting tools. Nevertheless, conventional ring spanners have low driving torque. Ratchet type ring spanners have been proposed to solve this problem. A ratchet wheel is mounted in the box end of a ring spanner for driving fasteners at high torque. It is, however, found that, the structural strength of the ratchet wheel is weak as an outer periphery of the ratchet wheel is processed to form a plurality of arcuate teeth with a considerable depth. U.S. patent application Ser. No. 09/365,738 proposes a ratchet wheel with asymmetric arcuate concave teeth or non-arcuate concave teeth as well as ratchet type ring spanners with such ratchet wheel. The present invention is intended to provide a ratchet wheel that is particularly suitable for socket wrenches.